This invention relates to the recovery of output or event detection from individual pixel sites and more specifically relates to a technique that digitizes analog voltage from the unit cell. In one embodiment a capacitor at the unit cell is not required.
A common technique to digitize an analog current output from each photo detector in an array uses a capacitor to integrate the current output into a proportional voltage level which is then converted into digital signal by an analog to digital converter. As pitches, i.e. the distance between adjacent photo detectors, in large arrays gets smaller to achieve increasing finer image resolution, the smaller resulting area available for the capacitors may lead to the use of capacitors with smaller capacitance values. This may degrade the dynamic range and performance of the processing of the photo detector output. Thus, there exists a need to be able to accommodate increasingly dense photo detector arrays and the associated area restrictions per cell site.